| 摘要 |
PURPOSE:To prevent picture quality deteriorating and to improve entire compressibility by performing orthogonal transformation after converting an image signal to a differential signal by using a prediction function utilizing neighboring picture element correlation. CONSTITUTION:A horizontal low-pass filter 101, a vertical low-pass filter 102, adders 103-105, 107, and a predictor 106 are provided, and the band separation of the image signal is performed on a spatial frequency. Then, the orthogonal transformation is performed after an original image signal is converted to the differential signal by using the prediction function utilizing the neighboring picture element correlation in the encoding of a low-pass area, and the orthogonal transformation is performed as it is in the encoding of a high-pass area, and multiplexing is performed after quantization, respectively. Thereby, it is possible to prevent the picture quality deteriorating and to improve the entire compressibility. |
